Alexandee vogelsang



ALEXANDER voeELsANa'oF new YORK, hsslenoa TO THE voentsnna soREwPROPELLEB QOMPANY'," or BROOKLYN, NEW YORK,

- SCREW-PFiOiPE-LL ER;

SPECIFICATION forming part of Letters Patent No. 381.193. datd April 17,1888, i i

Application men November 23, 1887. Serial nast est. (ModeL) V i To allwhom it may concern:

Be it knownthat I, ALEXANDER VOGEL: SANG, a citizen of the UnitedStates, residing at New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements inScrew-Propellers; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame. l

My invention relates to screw-propellers; and it has for its object animprovement on my propeller patented April 5, 1887, N01 360,833, In thefurther development' of my invention by practical demonstration onseagoing vessels I have discovered that better results are obtained froma screw-propeller in'which the leading pointof the cutting-edge of eachblade is in advance of the part of the next preceding blade (in thedirection in which the vessel is moving) in the same radius than from ascrew-propeller in which the leading point of the cuttingedge of eachalternate blade only an elevation or side view showing the relation isin advance of the part of the next preceding blade in the same radius;

The invention will be hereinafter described, and particularly pointedout in the claims.

In the accompanying drawings, which form a part of this specification,Figure 1 is an'end view of my improved propeller with the lines ofconstruction drawn on one blade,and Fig.2 is

of the leading point of the cutting-edge of one blade to the others andthe overlapping oftwo adjacent blades. Y

Reference being had to the drawings and the letters thereon, Arepresents the hub, from I which radiates a series ofblades, B,whic hmay The cutting or entering edge of each =1 UNITED STATES"PATENT:OFFICEQ"a" thatpart of the preceding blade in the same radius,and theleading point d ofthe bladesis in advance of that part of the precedingblade in a corresponding'radius. The blades,(w henarranged in pairs,)which are diametrically opposite'to each other on the hub, havetheir i pcutting or-entering and their trailing or leav j ing edges made toconform to each other; The i contour of one of the edges of eachblademaybe composed of lines radiating from'different centers, or right linesand curved line's combined, and the opposite edge of each blade-may bein the form of an ogee or cyma, or it may be a curved line struck fromone center and at the hub; or the lines may be angular where s reachingfrom the end of the blade to the root 1 they radiate from the hub andintersect a curved line from the end of the blade; The

principal feature in the construction is that the leading points 0 or dof the cutting-edges of two succeeding blades are in advanceof 7eachother, or are situated at different distances from theoenterof thescrew-.that is, the lead-,-, V

blade, as shown at c, and the leadingpointd ing point of thecutting-edge of one blade is near the circumference or periphery of theof the next preceding blade is near the hub.-

The leading point of each; blade always falls in a planethat is inadvance of the preceding blade in the direction in which the vessel ismoving when the screw is viewed from-a side elevation.

otherwords, the blades havingtheirleading points of the cutting-edgenearthecircumfer ence or periphery of the blade are in advance of the partof the next-preceding blade in the same radius, While the leadingpoints'of; the cutting-edges which are near the hub. on the nextpreceding blades arein the same plane;

I The roots of the blades are disposed upon 5 the hub at an angle to thelongitudinal axis of the hub, andthe centers of the working surfaces'ofeach pair of blades ar e curved in opposite'directions, while the'centers'of the I blades which radiate at rightanglesthrough, root theaxis of the screw cut the blades, so that the major portion of theblades is on the convex side or trailing edge of one pair of bladesandthe convex side or cutting-edge of the opposite pair of blades, asshown at e on each blade.

The pitch of the blades may be uniform fromthe hub to the periphery orends of the blades, or it may be of an expanding or a variable pitch, orthe blades may be flatand set at a suitable angle to the shaft; but ineither construction all of the blades must be either right or all leftscrews.

One blade of each pair overlaps or crosses the plane of rotation of theadjacent blade of the next pair of blades, as shown in Fig. 2, and atransverse vertical line through the blades and the hub strikes eachblade at the point of intersection or crossing of theblades.

The construction lines and the dotted lines showing the development ofthe blade are well pnilerstood and require no description in de- By theconstruction shown each blade presents a leading point on thecutting-edge in advance of the same part of the preceding blade in thesame radius, so that the same speed is obtained in either direction'inwhich plane of the part of the'next preceding blade in thesame radiusand in the plane of rotation of the screw, substantially as described.

2. A propeller in which the leading parts of two successive blades aresituated at diflerent distances from the hub in a plane which is normalto the axis of the propeller-shaft and the blades diametrically oppositeeach other are alike, substantially as described.

In testimony whereof I atfix my signature in presence of two witnesses.

ALEXANDER VOGELSANG.

Witnesses:

WILLIAM H. STILLWELL, T. J. DIXON.

